Detecting actuations of buttons of a control device

ABSTRACT

A load control device may be used to control and deliver power to an electrical load. The load control device may comprise a control circuit for controlling the power delivered to the electrical load. The load control device may comprise multiple actuators, where each of the actuators is connected between a terminal of the control circuit and a current regulating device. The number of the actuators may be greater than the number of the terminals. The control circuit may measure signals at the terminals and determine a state configuration for the actuators based on the measured signals. The control circuit may compare the state configuration to a predetermined dataset to detect a ghosting condition.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/977,657, filed on May 11, 2018, which claims priority to ProvisionalU.S. Patent Application No. 62/504,653, filed May 11, 2017, the entiredisclosures of which are incorporated by reference herein.

BACKGROUND

Home automation systems, which have become increasing popular, may beused by homeowners to integrate and control multiple electrical and/orelectronic devices in their house. For example, a homeowner may connectappliances, lights, blinds, audio systems, thermostats, cable orsatellite boxes, security systems, telecommunication systems, or thelike to each other via a wireless network. The homeowner may controlthese devices using a controller or a user interface provided via aphone, a tablet, a computer, and the like directly connected to thenetwork or remotely connected via the Internet. These devices maycommunicate with each other and the controller to, for example, improvetheir efficiency, their convenience, and/or their usability.

A controller (e.g., a load control device) may include multipleactuators and a control circuit, where each actuator may be configuredto control one or more electrical loads, such as those described withrespect to home automation. The control circuit may include anintegrated circuit (IC) having a preconfigured number of terminals(e.g., pins), where each actuator is coupled to one or more of theterminals. For example, each actuator may be coupled between two of theterminals or between one of the terminals and a reference (e.g., such asa supply voltage or circuit common). The number of terminals of thecontrol circuit limits the number of actuators of the control device.One way to increase the number of actuators of a load control devicewithout changing the number of terminals of the control circuit is toadopt a multiplexing technique, such as a charlieplexing technique. Thecharlieplexing technique may enable the reading of up to N(N−1)actuators using N terminals. For example, the charlieplexing techniquemay enable the reading of up to six actuators using three terminals.

FIG. 1 is a diagram of an example prior art circuit 100 that isconfigured to perform the charlieplexing technique. The circuit 100includes a processing device 102 (e.g., microprocessor) that has threeterminals 104, 106, 108 (e.g., pins). Since the processing device 102 isconfigured to perform the charlieplexing technique and includes threeterminals 104, 106, 108, the circuit 100 may include up to six actuators112-122, where each actuator 112-122 is electrically coupled in serieswith a respective diode 124-134. Further, each actuator 112-122 iselectrically coupled between two terminals of terminals 104-108. Eachdiode 124-134 is configured to conduct current in one direction andblock current in the opposite direction. The diodes 124-134 help toensure that the processing device 102 can distinguish which actuator112-122 is being actuated. For example, the path from terminal 108 toterminal 104 passes through actuator 120 but not through actuator 122,because diode 134 blocks current from flowing from terminal 108 toterminal 104. In another example, the path from terminal 106 to terminal108 passes through actuator 118 but not through actuator 116, becausediode 128 blocks current from flowing from terminal 106 to terminal 108.As such, the processing device 102 can determine whether a particularactuator 112-122 is actuated by pulling down terminals (e.g., terminals104, 106) and driving one terminal (e.g., terminal 108) high towards asupply voltage. The processing device 102 may measure the states atterminals that are pulled down (e.g., terminals 104, 106). For example,if the processing device 102 measures that terminal 104 is in a highstate, then the processing device 102 may determine that actuator 120 isactuated (e.g., as shown in FIG. 1). For further example, if theprocessing device 102 pulls down terminals 104 and 108, drives terminal106 high towards the supply voltage, and measures that terminal 108 isin a high state, then the processing device 102 may determine that theactuator 118 is actuated.

However, by simply reading the states of terminals to determine whetheran actuator is being actuated, the processing device 102 may erroneouslydetermine that a particular actuator has been actuated when in factmultiple actuators have been actuated. This may be referred to as aghosting condition and result in a faulty operation by the circuit 100.A ghosting condition may occur when there are multiple current pathsbetween the two terminals, for example, by actuation of multipleactuators. For example, if actuators 112 and 116 are pressed (e.g., theuser accidently hits two buttons at once), the processing device 102 mayerroneously determine that actuator 120 has been pressed and the circuit100 may perform the associated function. In this example, the processingdevice 102 may drive terminal 108 high and determine that terminal 104is in a high state. The processing device 102 may associate this stateconfiguration with the actuation of actuator 120 even though actuator120 was not actuated by the user.

SUMMARY

A load control device may be used to control and deliver power to anelectrical load. The load control device may comprise a control circuitfor controlling the power delivered to the electrical load via multipleterminals. The load control device may comprise an actuator inputcircuit including multiple actuators that are coupled between theterminals and devices that allow current to pass in one direction andblocks the current in the opposite direction. The number of theactuators may be greater than the number of the terminals. The controlcircuit may measure a signal at a terminal connected with an actuatorand compare the measured signal to a threshold that is calculated from avoltage drop caused by the device. The control circuit may determinethat the actuator connected with the terminal has been actuated when themeasured signal is less than the threshold calculated from the voltagedrop of the device. The device may be a diode and the voltage drop maybe a diode drop. The threshold may be calculated from a single diodedrop and a supply voltage signal of the control circuit.

The control circuit may compare the measured signal to a thresholdcalculated from more than one voltage drops when the measured signal isno less than the threshold calculated from the single diode drop. Thecontrol circuit may mark the actuator as quarantined when the measuredsignal is less than the threshold calculated from more than one voltagedrops, or mark the actuator as open when the measured signal is no lessthan the threshold calculated from more than one voltage drops. Thecontrol circuit may continue to determine whether the other actuatorsare activated. The control circuit may determine an error occurs whenthe actuators that are actuated are associated with an invalid currentpath.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram of a prior art load control device that isconfigured to perform charlieplexing.

FIG. 2 is a diagram of an example of a load control system comprisingvarious load control devices and electrical loads.

FIG. 3 is a perspective view of an example of a load control device.

FIG. 4 is a simplified block diagram of an example of a load controldevice.

FIG. 5 is a diagram of an example of an actuator input circuit and acontrol circuit that is configured to perform a charlieplexing techniqueand detect a ghosting condition.

FIG. 6 is a diagram of another example of an actuator input circuit anda control circuit that is configured to perform a charlieplexingtechnique and detect a ghosting condition.

FIG. 7 is a flowchart illustrating an example of a control procedureperformed by a control circuit of a load control device.

DETAILED DESCRIPTION

FIG. 2 is a simple diagram of an example load control system 200 (e.g.,a lighting control system) in which one or more input devices such as awall-mounted remote control device 240 (e.g., the load control device300, and/or other example load control devices described herein) may bedeployed. The wall-mounted remote control device 240 may include one ormore actuation members 242. The wall-mounted remote control device 240may not be directly connected to an electrical load, and as such, maynot include an internal load control circuit.

The wall-mounted remote control device 240 may transmit signals, e.g.,radio-frequency (RF) signals 206, in response to actuations of one ormore of the actuation members 242. For example, the remote controldevice 240 may transmit the RF signals 206 to an electrical load(s)and/or to a load control device(s) (e.g., which is directly orindirectly connected to an electrical load) for controlling one or morecharacteristics of the electrical load (e.g., such as light intensity,light color and/or color temperature, volume, shade level, temperature,fan speed, etc.). In an example, a wall-mounted load control device 210may be configured to receive the RF signals 206 transmitted by thewall-mounted remote control device 240 to control a light bulb 212 inresponse to the actuation of a member of the plurality of actuationmembers 242 of the wall-mounted remote control device 240. For example,the RF signals 206 may be transmitted at a communication frequencyf_(RF) (e.g., approximately 434 MHz) using a proprietary RF protocol,such as the ClearConnect® protocol. The remote control device 240 maytransmit RF signals 206 at one or more communication frequencies, suchas, for example, 2.4 GHz or 5.6 GHz. The RF signals 206 may betransmitted using a different RF protocol, such as, for example, one ofWIFI, ZIGBEE, Z-WAVE, BLUETOOTH, THREAD, KNX-RF, ENOCEAN RADIOprotocols, or a different proprietary protocol.

The actuation members 242 of the wall-mounted remote control device 240(e.g., a wall-mounted keypad device) may actuated to select one or morepresets or scenes, such as “All on,” “Welcome,” “Day,” “Patio,”“Evening,” “Entertain,” “Goodnight,” or “Night Light.” Each of thepresets or scenes may be associated with unique operational settings ofone or more electrical loads. An operational setting of an electricalload may include, for example, a light intensity, a light color, a lightcolor temperature, a volume level, an HVAC setting (e.g., temperature,fan speed, etc.), a window treatment setting, and/or the like. A usermay configure the scenes of the wall-mounted remote control device 240,for example, by placing the wall-mounted remote control device 240 intoa special programming mode, via a network device 290, such as asmartphone, and/or the like.

The wall-mounted load control device 210 may be coupled in seriesbetween an AC power source 202 and a first lighting load, e.g., firstlight bulb 212 that may be installed in a ceiling mounted downlightfixture 214. The first light bulb 212 may be installed in a wall-mountedlighting fixture or other lighting fixture mounted to another surface.The wall-mounted load control device 210 may be adapted to bewall-mounted in a standard electrical wallbox. The load control system200 may include another load control device, e.g., a plug-in loadcontrol device 220. The plug-in load control device 220 may be coupledin series between the AC power source 202 and a second lighting load,e.g., a second light bulb 222 installed in a lamp (e.g., a table lamp224). The plug-in load control device 220 may be plugged into anelectrical receptacle 226 that is powered by the AC power source 202.The table lamp 224 may be plugged into the plug-in load control device220. The second light bulb 222 may be installed in a table lamp or otherlamps that may be plugged into the plug-in load control device 220. Theplug-in load control device 220 may be implemented as a table-top loadcontrol device, or a remotely-mounted load control device.

The wall-mounted load control device 210 may include a touch sensitiveactuator 216 for controlling the first light bulb 212. In response toactuation of the touch sensitive actuator 216, the wall-mounted loadcontrol device 210 may be configured to turn the first light bulb 212 onand off, and to increase or decrease the amount of power delivered tothe first light bulb. The wall-mounted load control device 210 may varythe intensity of the light bulb by varying the amount of power deliveredto the light bulb. The wall-mounted load control device 210 may increaseor decrease the intensity of the light bulb from a minimum intensity(e.g., approximately 1%) to a maximum intensity (e.g., approximately100%). The wall-mounted load control device 210 may be configured toprovide visual indicators. The visual indicators may be arranged in alinear array on the touch sensitive actuator 216. The wall-mounted loadcontrol device 210 may be configured to illuminate the visual indicatorsto provide feedback of the intensity of the first light bulb 212.Examples of wall-mounted dimmer switches are described in greater detailin U.S. Pat. No. 5,248,919, issued Sep. 28, 1993, entitled LIGHTINGCONTROL DEVICE, and U.S. Patent Application Publication No.2014/0132475, published May 15, 2014, entitled WIRELESS LOAD CONTROLDEVICE, the entire disclosures of which are hereby incorporated byreference.

The load control system 200 may include a daylight control device, e.g.,a motorized window treatment 230, mounted in front of a window forcontrolling the amount of daylight entering the space in which the loadcontrol system 200 is installed. Examples of battery-powered motorizedwindow treatments are described in greater detail in commonly-assignedU.S. Pat. No. 8,950,461, issued Feb. 10, 2015, entitled MOTORIZED WINDOWTREATMENT, and U.S. Pat. No. 9,115,537, issued Aug. 25, 2015, entitledBATTERY-POWERED ROLLER SHADE SYSTEM, the entire disclosures of which arehereby incorporated by reference.

The one or more input devices (e.g., RF transmitters) in the loadcontrol system 200 may include also a battery-powered handheld remotecontrol device 250, an occupancy sensor 260, or a daylight sensor 270.The wall-mounted load control device 210 and/or the plug-in load controldevice 220 may be configured to receive digital messages via the RFsignals 206. The wireless signals may be transmitted by the wall-mountedremote control device 240, the battery-powered remote control device250, the occupancy sensor 260, or the daylight sensor 270. In responseto the received digital messages, the wall-mounted load control device210 and/or the plug-in load control device 220 may be configured to turnthe respective light bulbs 212, 222 on and off, and to increase ordecrease the intensity of the respective light bulbs. The wall-mountedload control device 210 and/or the plug-in load control device 220 maybe implemented as electronic switches configured to turn on and off(e.g., only turn on and off) the respective light bulbs 212, 222.

The battery-powered remote control device 250 may include one or moreactuators 252 (e.g., one or more of an on button, an off button, a raisebutton, a lower button, and a preset button). The battery-powered remotecontrol device 250 may transmit RF signals 206 in response to actuationsof one or more of the actuators 252. The battery-powered remote controldevice 250 may be handheld. The battery-powered remote control device250 may be mounted vertically to a wall or supported on a pedestal forplacement on a tabletop. Examples of battery-powered remote controldevices are described in greater detail in commonly-assigned U.S. Pat.No. 8,330,638, issued Dec. 11, 2012, entitled WIRELESS BATTERY-POWEREDREMOTE CONTROL HAVING MULTIPLE MOUNTING MEANS, and U.S. PatentApplication Publication No. 2012/0286940, published Nov. 15, 2012,entitled CONTROL DEVICE HAVING A NIGHTLIGHT, the entire disclosures ofwhich are hereby incorporated by reference.

The occupancy sensor 260 may be configured to detect occupancy andvacancy conditions in the space in which the load control system 200 isinstalled. The occupancy sensor 260 may transmit digital messages to thewall-mounted load control device 210 and/or the plug-in load controldevice 220 via the RF signals 206 in response to detecting the occupancyor vacancy conditions. Each of the wall-mounted load control device 210and/or the plug-in load control device 220 may be configured to turn onthe respective light bulb 212, 222 in response to receiving an occupiedcommand. The wall-mounted load control device 210 and/or the plug-inload control device 220 may be configured to turn off the respectivelight bulb in response to receiving a vacant command. Examples of RFload control systems having occupancy and vacancy sensors are describedin greater detail in commonly-assigned U.S. Pat. No. 8,009,042, issuedAug. 30, 2011 Sep. 3, 2008, entitled RADIO-FREQUENCY LIGHTING CONTROLSYSTEM WITH OCCUPANCY SENSING; U.S. Pat. No. 8,199,010, issued Jun. 12,2012, entitled METHOD AND APPARATUS FOR CONFIGURING A WIRELESS SENSOR;and U.S. Pat. No. 8,228,184, issued Jul. 24, 2012, entitledBATTERY-POWERED OCCUPANCY SENSOR, the entire disclosures of which arehereby incorporated by reference.

The daylight sensor 270 may be configured to measure a total lightintensity in the space in which the load control system 200 isinstalled. The daylight sensor 270 may transmit digital messagesincluding the measured light intensity to the wall-mounted load controldevice 210 and/or the plug-in load control device 220. The daylightsensor 270 may transmit digital messages via the RF signals 206 forcontrolling the intensities of the respective light bulbs 212, 222 inresponse to the measured light intensity. Examples of RF load controlsystems having daylight sensors are described in greater detail incommonly-assigned U.S. Pat. No. 8,410,706, issued Apr. 2, 2013, entitledMETHOD OF CALIBRATING A DAYLIGHT SENSOR; and U.S. Pat. No. 8,451,116,issued May 28, 2013, entitled WIRELESS BATTERY-POWERED DAYLIGHT SENSOR,the entire disclosures of which are hereby incorporated by reference.

Digital messages transmitted by the input devices (e.g., thewall-mounted remote control device 240, the battery-powered remotecontrol device 250, the occupancy sensor 260, and the daylight sensor270) may include a command and/or identifying information. Each of theinput devices may be assigned to the wall-mounted load control device210 and/or the plug-in load control device 220 during a configurationprocedure of the load control system 200, such that the wall-mountedload control device 210 and/or the plug-in load control device 220 areresponsive to digital messages transmitted by the input devices via theRF signals 206. Examples of methods of associating wireless controldevices are described in greater detail in commonly-assigned U.S. PatentApplication Publication No. 2008/0111491, published May 15, 2008,entitled RADIO-FREQUENCY LIGHTING CONTROL SYSTEM, and U.S. Pat. No.9,368,025, issued Jun. 14, 2016, entitled TWO-PART LOAD CONTROL SYSTEMMOUNTABLE TO A SINGLE ELECTRICAL WALLBOX, the entire disclosures ofwhich are hereby incorporated by reference.

The load control system 200 may include a gateway device 280 (e.g., abridge and/or a system controller) configured to enable communicationwith a network 282, e.g., a wireless or wired local area network (LAN).The gateway device 280 may be connected to a router (not shown) via awired digital communication link 284 (e.g., an Ethernet communicationlink). The router may allow for communication with the network 282,e.g., for access to the Internet. The gateway device 280 may bewirelessly connected to the network 282, e.g., using Wi-Fi technology.

The gateway device 280 may be configured to transmit RF signals 206 tothe wall-mounted load control device 210 and/or the plug-in load controldevice 220 (e.g., using the proprietary protocol) for controlling therespective light bulbs 212, 222 in response to digital messages receivedfrom external devices via the network 282. The gateway device 280 may beconfigured to receive RF signals 206 from the wall-mounted load controldevice 210, the plug-in load control device 220, the motorized windowtreatment 230, the wall-mounted remote control device 240, thebattery-powered remote control device 250, the occupancy sensor 260,and/or the daylight sensor 270 (e.g., using the proprietary protocol).The gateway device 280 may be configured to transmit digital messagesvia the network 282 for providing data (e.g., status information) toexternal devices. The gateway device 280 may operate as a centralcontroller for the load control system 200, or may simply relay digitalmessages between the control devices of the load control system and thenetwork 282.

The load control system 200 may include a network device 290, such as, asmart phone (for example, an iPhone® smart phone, an Android® smartphone, or a Blackberry® smart phone), a personal computer, a laptop, awireless-capable media device (e.g., MP3 player, gaming device, ortelevision), a tablet device, (for example, an iPad® hand-held computingdevice), a Wi-Fi or wireless-communication-capable television, or anyother suitable Internet-Protocol-enabled device. The network device 290may be operable to transmit digital messages in one or more InternetProtocol packets to the gateway device 280 via RF signals 208 eitherdirectly or via the network 282. For example, the network device 290 maytransmit the RF signals 208 to the gateway device 280 via a Wi-Ficommunication link, a Wi-MAX communications link, a Bluetooth®communications link, a near field communication (NFC) link, a cellularcommunications link, a television white space (TVWS) communication link,or any combination thereof. Examples of load control systems operable tocommunicate with network devices on a network are described in greaterdetail in commonly-assigned U.S. Patent Application Publication No.2013/0030589, published Jan. 31, 2013, entitled LOAD CONTROL DEVICEHAVING INTERNET CONNECTIVITY, the entire disclosure of which is herebyincorporated by reference.

The network device 290 may include a visual display 292. The visualdisplay 292 may include a touch screen that may include, for example, acapacitive touch pad displaced overtop the visual display, such that thevisual display may display soft buttons that may be actuated by a user.The network device 290 may include a plurality of hard buttons, e.g.,physical buttons (not shown), in addition to the visual display 292. Thenetwork device 290 may download a product control application forallowing a user of the network device to control the load control system200. In response to actuations of the displayed soft buttons or hardbuttons, the network device 290 may transmit digital messages to thegateway device 280 through the wireless communications described herein.The network device 290 may transmit digital messages to the gatewaydevice 280 via the RF signals 208 for controlling the wall-mounted loadcontrol device 210 and/or the plug-in load control device 220. Thegateway device 280 may be configured to transmit RF signals 208 to thenetwork device 290 in response to digital messages received from thewall-mounted load control device 210, the plug-in load control device220, the motorized window treatment 230, the wall-mounted remote controldevice 240, the battery-powered remote control device 250, the occupancysensor 260, and/or the daylight sensor 270 (e.g., using the proprietaryprotocol) for displaying data (e.g., status information) on the visualdisplay 292 of the network device.

The operation of the load control system 200 (e.g., the associationbetween the input devices and/or remote control devices and the loadcontrol devices, the presets, etc.) may be programmed and configuredusing the gateway device 280 and/or network device 290. An example of aconfiguration procedure for a wireless load control system is describedin greater detail in commonly-assigned U.S. Patent Publication No.2014/0265,568, published Sep. 18, 2014, entitled COMMISSIONING LOADCONTROL SYSTEMS, the entire disclosure of which is hereby incorporatedby reference. Examples of wireless load control systems are described ingreater detail in commonly-assigned U.S. Pat. No. 5,905,442, issued May18, 1999, entitled METHOD AND APPARATUS FOR CONTROLLING AND DETERMININGTHE STATUS OF ELECTRICAL DEVICES FROM REMOTE LOCATIONS; and U.S. PatentApplication Publication No. 2009/0206983, published Aug. 20, 2009,entitled COMMUNICATION PROTOCOL FOR A RADIO-FREQUENCY LOAD CONTROLSYSTEM, the entire disclosures of all of which are hereby incorporatedby reference.

FIG. 3 is a perspective view of an example load control device 300. Theexample load control device 300 may be configured to operate as awall-mounted remote control device (e.g., such as the wall-mountedremote control device 240) of a load control system (e.g., the loadcontrol system 200 shown in FIG. 2). The load control device 300 mayinclude one or more actuation members 312 for controlling an electricalload (e.g., a lighting load). The actuation members 312 may be examplesof the plurality of actuation members 242. The one or more actuationmembers 312 may be provided as a keypad.

The load control device 300 may include a bezel 314. The bezel 314 maybe shaped to form one or more openings separated by one or more dividers316, through which the front surface of the one or more actuationmembers 312 or different portions of an actuation member (e.g., when anactuation member has an upper portion and a lower portion) may extend.The load control device 300 may be used for controlling the powerdelivered from an alternating-current (AC) source to an electrical load(e.g., a lighting load).

The load control device 300 may comprise a faceplate 302, an air-gapactuator 329, and an enclosure 326. The faceplate 302 may define aplanar front surface of the load control device 300 and may have anopening 306 for receiving the bezel 314 and one or more actuationmembers 312 that are configured to receive user inputs. The opening 306may be adapted to receive the one or more actuation members 312, forexample, when the faceplate 302 is installed on the wireless controldevice 300. The one or more actuation members 312 may be arranged alonga longitudinal axis of the load control device 300. The faceplate 302may comprise a light-conductive body portion 305 and opaque materialprovided on a front surface 307 of the faceplate. Indicia (e.g., textand/or graphics) may be engraved in the opaque material and beilluminated by one or more light sources residing behind the bodyportion 305 and within the load control device 300.

The one or more actuation members 312 may be buttons and may be made ofa non-conductive material, such as plastic or glass, or of a conductivematerial, such as a metallic sheet attached to a plastic carrier. Theone or more actuation members 312 may each be designated to select oneor more operational settings (e.g., presets, scenes, and/orpredetermined light intensities) associated with a specific usescenario, such as “Welcome,” “Day,” “Entertain,” or “Goodnight.” Anoperational setting may refer to predetermined and/or configurableoperational parameters of one or more electrical loads, for example,light intensity, HVAC setting (e.g., temperature), window treatmentsetting, and/or the like. The specific use scenario associated with eachof the actuation members 312 may be indicated, for example, by placinglabels next to the actuation members 312 describing their associated usescenarios, such as “Welcome,” “Day,” “Entertain,” or “Goodnight.” Theload control device 300 may be configured to transmit RF signals to oneor more load control devices and/or one or more electrical loads inresponse to actuations of the actuation members 312.

FIG. 4 is a simplified block diagram of an example control device 400,which may be implemented as a load control device (e.g., the remote loadcontrol device 240, the load control device 300, etc.) and/or remoteinput device (e.g., the remote control device 250). The control device400 may comprise a control circuit 414, a wireless communication circuit404, a memory 420, an actuator input circuit 416, one or more visualindicators 418, a power supply 422, and a power supply connector 426.

The control circuit 414 may include one or more of a processor (e.g., amicroprocessor), a microcontroller, a programmable logic device (PLD), afield programmable gate array (FPGA), an application specific integratedcircuit (ASIC), or any suitable processing device. The control circuit414 may perform signal coding, data processing, power control,input/output processing, and/or any other functionality that enables thecontrol device 400 to perform as described herein.

The wireless communication circuit 404 may include an RF transceivercoupled to an antenna for transmitting and/or receiving RF signals. Thewireless communication circuit 404 may communicate via a Wi-Ficommunication link, a Wi-MAX communications link, a Bluetooth®communications link, a near field communication (NFC) link, a cellularcommunications link, a television white space (TVWS) communication link,a proprietary protocol (e.g., the ClearConnect® protocol), or anycombination thereof. The control circuit 414 may be coupled to thewireless communication circuit 404 for transmitting digital messages viathe RF signals, for example, to control load control devices in the loadcontrol environment in response to received digital messages. Thecontrol circuit 414 may be configured to receive digital messages, forexample, from the load control devices and/or the input devices. Thecontrol circuit 414 may be configured to transmit RF signals upon anactuator of actuator input circuit 416 being actuated.

The control circuit 414 may respond to actuations of the actuator inputcircuit 416. For example, the control circuit 414 may be operable toassociate the control device 400 with one or more control devices inresponse to actuations of the actuator input circuit 416 during aconfiguration procedure of a load control system. The control circuit414 may individually control the visual indicators 418 in response toactuations of the actuator input circuit 416, for example, to illuminatea linear array of visual indicators on a load control device.

The control circuit 414 may store information in and/or retrieveinformation from the memory 420. The memory 420 may include anon-removable memory and/or a removable memory for storingcomputer-readable media. The non-removable memory may includerandom-access memory (RAM), read-only memory (ROM), a hard disk, and/orany other type of non-removable memory storage. The removable memory mayinclude a subscriber identity module (SIM) card, a memory stick, amemory card (e.g., a digital camera memory card), and/or any other typeof removable memory. The control circuit 414 may access the memory 420for executable instructions and/or other information that may be used bythe control device 400. The memory 420 may be communicatively coupled tothe control circuit 414 for the storage and/or retrieval of, forexample, operational settings, such as, a dataset indicating validcurrent paths between multiple integrated circuit terminals of thecontrol circuit 414. The memory 420 may be implemented as an externalintegrated circuit (IC) or as an internal circuit of the control circuit414.

The control circuit 414 may illuminate a visual indicator 418 to providefeedback to a user of a load control system. For example, the controlcircuit 414 may blink or strobe the visual indicator 418 to indicate afault condition. The control circuit 414 may be operable to illuminatethe visual indicator 418 with different colors to indicate differentconditions or states of the control device 400. The visual indicator 418may be illuminated by, for example, one or more light-emitting diodes(LEDs). The control device 400 may include more than one visualindicator.

The control device 400 may include a power supply 422 for generating aDC supply voltage V_(CC) for powering the control circuit 414, thewireless communication circuit 416, the memory 420, the visual indicator418, and/or other circuitry of the control device 400. The power supply422 may be coupled to the power supply connector 426 (e.g., a USB port)for receiving a supply voltage (e.g., a DC voltage) and/or for drawingcurrent from an external power source.

Each actuator may be configured to control one or more electrical loadsvia the wireless communication circuit 404. Further, the actuator inputcircuit 416 may be associated with a different action for the sameload(s) (e.g., different intensity levels for one or more lightingloads) and/or associated with different load(s) (e.g., lighting loads,an HVAC system, motorized window treatments, and/or the like). Forexample, a first actuator may control a first group of lighting loads toa first level and window treatments to a preset level, and a secondactuator may control the first group of lighting loads to a second leveland a second group of lighting loads to a set level. Additionally, theactuation of a particular combination of actuators may perform a specialfunction, such as placing the control device 400 into an advancedprogramming mode. Once in the advanced programming mode, a user mayconfigure the actuator input circuit 416 of the control device 400 tocontrol different electrical loads of the system (e.g., the load controlsystem 200) and/or control one or more electrical loads to a differentlevel (e.g., intensity).

The control circuit 414 (e.g., a processor of the control circuit) maycomprise multiple terminals, which may be used to couple the controlcircuit 414 to the actuator input circuit 416. The number of actuatorsmay be greater than the number of terminals, and, for example, thecontrol circuit 400 may include N terminals and up to N(N−1) actuators,where each terminal is connected to one or more actuators. Further, eachactuator of the actuator input circuit 416 may be associated with acurrent regulating device, such as a blocking semiconductor device(e.g., a diode).

The control circuit 414 may be configured to detect occurrences ofghosting conditions. For example, the control circuit 414 may apply asignal (e.g., an electrical current and/or voltage) to one or moreterminals, measure a received signal at one or more terminals, andcompare the received signals to one or more predetermined thresholds todetermine whether a ghosting condition has occurred (e.g., as describedherein). For example, the control circuit 414 may be configured to pulldown one or more terminals and measure a voltage (e.g., voltagepotential) at each of the terminals to determine a state for each of theterminals. The current signal may flow through a current path betweenthe first and second terminals, and there may be one or more actuators(e.g., and associated current regulating devices) coupled between thetwo terminals along the current path. An analog voltage may be measuredat one of the terminals and compared to one or more thresholds to detectthe ghosting condition. As described herein, the thresholds may bedetermined based on characteristics of the current regulating devices ofthe control device 400. For example, the thresholds may be determinedbased on one or more diode drops (e.g., voltage drops across the diodesof the control device 400) if the current regulating devices are diodes.

FIG. 5 is a diagram of an example actuator input circuit 500 and anexample control circuit 540 that may be configured to perform acharlieplexing technique and detect ghosting conditions. The controlcircuit 540 may be an example of the control circuit 414 of the controldevice 400, and the actuator input circuit 500 may be an example of theactuator input circuit 416 of the control device 400. The controlcircuit 540 (e.g., a processor, such as a microprocessor) may include aplurality of terminals 542-548. The control circuit 540 may include ananalog-to-digital converter (ADC) (e.g., or multiple comparators). Thecontrol circuit 540 may configure each of the terminals 542-548 as aninput terminal or an output terminal. When one of the terminals 542-548is configured as an output terminal, the control circuit 540 may beconfigured to “short” the terminal to the supply voltage (e.g., thesupply voltage V_(CC)) and/or circuit common, e.g., through respectiveinternal field-effect transistors (FETs). When one of the terminals542-548 is configured as an input terminal, the control circuit 540 maybe configured to pull the terminal up towards the supply voltage and/orpull the terminal down towards circuit common through respectiveinternal resistors (e.g., pull-up and pull-down resistors). In addition,when one of the terminals 542-548 is configured as an input terminal,the control circuit 540 may be configured as a standard logic input(e.g., as either a logic high or a logic low) or an ADC input. Thecontrol circuit may also control each of the terminals 542-548 to ahigh-impedance state in which the terminals are not configured as inputor output terminals (e.g., the terminals are not shorted to or pulledtowards the supply voltage or circuit common).

As shown in FIG. 5, the four terminals 542-548 of the control circuit540 may be connected to the actuator input circuit 500. The actuatorinput circuit 500 may include a plurality of actuators 501-512 and aplurality of respective current regulating devices, such as diodes521-532. The control circuit 540 may be configured to perform acharlieplexing technique via the terminals 542-548, which may allow theterminals 542-548 of the control circuit 540 to be connected to up toN(N−1) actuators, where N is the number of terminals. The actuator inputcircuit 500 may comprise a maximum allowable number N_(MAX) of actuatorsthat can be configured for charlieplexing with the terminals 542-548 ofthe control circuit 540, e.g., where N_(MAX)=N(N−1). For example, whenthe number N of terminals equals 4, the maximum allowable number N_(MAX)of actuators may be 12.

The actuator input circuit 500 may include, for example, one respectivediode 521-532 associated with each actuator 501-512. Each actuator501-512 may be coupled between two of terminals 542-548 and may becoupled in series with one of the diodes 521-532. For example, actuator501 may be coupled between terminals 544 and 542 and coupled in serieswith diode 521, and actuator 512 may be coupled between terminals 546and 548 and coupled in series with diode 532.

Each diode 521-532 may be configured to conduct current in one directionand block current in the opposite direction. The diodes 521-532 may helpto ensure that the control circuit 540 can distinguish which actuator(s)501-512 is being actuated. For example, the path from terminal 544 toterminal 542 may pass through actuator 501 but not through actuator 504,because diode 524 may block current from flowing from terminal 544 toterminal 542. In another example, the path from terminal 546 to terminal548 may pass through actuator 512 but not through actuator 509, becausediode 529 may block current from flowing from terminal 548 to terminal546.

In order to determine if a particular actuator of the actuators 501-512is presently being actuated, the control circuit 540 may configure theterminals 542-548 to predetermined states before reading one of theterminals. For example, the control circuit 540 may configure a firstterminal that is connected to the cathode of the diode in series withthe particular actuator as an output, and may short the terminal tocircuit common. The control circuit 540 may configure a second terminalthat is connected to the anode of the diode in series with theparticular actuator as an input that is pulled up towards the supplyvoltage through an internal pull-up resistor, and may configure thesecond terminal as an ADC input. In addition, the control circuit 540may configure each of the remaining terminals to the high-impedancestate.

When the terminals 542-548 are configured correctly for the particularactuator, the control circuit 540 may measure the magnitude of thevoltage at the second terminal that is configured as an input pulled uptowards the supply voltage through a pull-up resistor. If the magnitudeof the voltage at the second terminal is high (e.g., at approximatelythe supply voltage), the control circuit 540 may determine that theparticular actuator is not presently being actuated. If the magnitude ofthe voltage at the second terminal is not high, but rather low (e.g.,approximately a diode drop above circuit common, such as 0.7 volts), thecontrol circuit 540 may determine that the particular actuator maypresently be being actuated.

Table 1 is an example of the state configurations for the terminals542-548 (e.g., Output Low, Input Pulled Up, and High Impendence (HighZ)) when the control circuit 540 is trying to determine if one of theactuators 501-512 is presently being actuated. The control circuit 540may configure the terminals 542-548 as shown in Table 1 for a particularactuator and measure the magnitude of the voltage at the terminals thatis configured as an input pulled up towards the supply voltage in orderto determine if the particular actuator in presently being actuated. Thecontrol circuit 540 may step through each actuator 501-512 and repeatthe process to determine if that actuator is presently being actuated.

TABLE 1 Example state configurations at the terminals Actuator Terminal542 Terminal 544 Terminal 546 Terminal 548 501 Output Low Input PulledUp High Z High Z 502 Output Low High Z Input Pulled Up High Z 503 OutputLow High Z High Z Input Pulled Up 504 Input Pulled Up Output Low High ZHigh Z 505 High Z Output Low Input Pulled Up High Z 506 High Z OutputLow High Z Input Pulled Up 507 Input Pulled Up High Z Output Low High Z508 High Z Input Pulled Up Output Low High Z 509 High Z High Z OutputLow Input Pulled Up 510 Input Pulled Up High Z High Z Output Low 511High Z Input Pulled Up High Z Output Low 512 High Z High Z Input PulledUp Output Low

If multiple actuators of the actuators 501-512 are pressed at one time,a ghosting condition may occur at the terminals 542-548. Without beingconfigured to detect the ghosting condition, a control circuit mayerroneously determine that a particular actuator has been actuated whenin fact multiple actuators have been actuated. For example, if actuators502 and 508 are pressed (e.g., the user accidently hits two buttons atonce), the control circuit 540 may erroneously determine that actuator501 has been pressed and the control circuit 540 may perform theassociated function corresponding to the actuation of actuator 501. Inthis example, the control circuit 540 may configure terminal 544 to bean input pulled-up high towards the supply voltage, configure the driveterminal 542 to be an output driven low towards circuit common, andconfigure terminals 546 and 548 to the high-impedance state. The controlcircuit 540 may measure the magnitude of the voltage at terminal 544,determine that the magnitude of the voltage at terminal 544 is not high(e.g., not at approximately the supply voltage), and thus come to aconclusion that actuator 501 is presently being actuated. If the controlcircuit 540 were to perform the function associated with actuator 501,the user may be confused since actuators 502 and 508 were pressed.

In addition, ghosting conditions may occur if three or more buttons arepressed at once. For example, if actuators 502, 509, and 511 are pressed(e.g., the user accidently hits three buttons at once), the controlcircuit 540 may erroneously determine that actuator 501 has been pressedand the control circuit 540 may perform the associated functioncorresponding to the actuation of actuator 501.

The control circuit 540 may be configured to be able to detect ghostingconditions. For example, the control circuit 540 may be configured toread (e.g., measure) the magnitude of the voltage at one of theterminals 542-548 to detect if ghosting is occurring. In addition, thecontrol circuit 540 may be configured to identify how many of theactuators and/or which actuators are presently being actuated. Thecontrol circuit 540 may be configured to use the ADC to measure themagnitude of the voltage at each of the terminals 542-548 and to convertthe analog value (e.g., the measured voltage) into a digital valuerepresentative of the magnitude of the voltage at the terminal.

The control circuit 540 may compare the magnitude of the measuredvoltage at each terminal 542-548 to a plurality of thresholds (e.g.,reference voltages). In the example where the control circuit 540configures terminal 544 to be an input pulled up towards the supplyvoltage, configure the drive terminal 542 to be an output driven lowtowards circuit common, and configures terminals 546 and 548 to the highimpedance state, the control circuit 540 may measure the magnitude ofthe voltage at terminal 544. The control circuit 540 may compare themagnitude of the measured voltage to one or more thresholds (e.g.,reference voltages), for example, to determine which and how many of theactuators 501-512 have been actuated. The control circuit 540 may alsodetermine that the user has actuated multiple actuators 501-512 onpurpose (e.g., to enter an advanced programing mode) or by mistake. Ifthe control circuit 540 determines that the user has actuated multipleactuators 501-512 by mistake, the control circuit 540 may notify theuser (e.g., by illuminating or flashing an LED on the actuator inputcircuit 500).

The thresholds may be determined (e.g., predetermined) based on a ratedvoltage (e.g., a rated forward voltage) associated with the currentregulating devices of the actuator input circuit 500 (e.g., the diodes521-532). Each of the one or more thresholds may be associated with arated forward voltage (e.g., a voltage drop) of one or more diodes(e.g., one diode drop, two diode drops, and/or three diode drops). Forexample, the control circuit 540 may utilize three thresholds V_(TH1),V_(TH2), V_(TH3), that may have values dependent upon the voltage dropsassociated with the voltage drops of one, two, and three diodes,respectively. A measured voltage less than the first threshold V_(TH1)may indicate a voltage drop of a single diode. A measured voltagegreater than the first threshold V_(TH1) and less than the secondthreshold V_(TH2) may indicate a voltage drop of two diodes. A measuredvoltage greater than the second threshold V_(TH3) and less than thethird threshold V_(TH3) may indicate a voltage drop of three diodes. Ifthe voltage drop associated with each diode 521-532 is approximately 0.7volts, then the first threshold V_(TH1) may be 1 volt, the secondthreshold V_(TH2) may be 1.7 volts, and the third threshold V_(TH3) maybe 2.4 volts.

The control circuit 540 may be configured to distinguish a singleactuated actuator from multiple actuated actuators, for example, bycomparing the measured voltage at one of the terminals to the one ormore thresholds V_(TH1), V_(TH2), V_(TH3). For example, when actuator501 is actuated, the magnitude of the voltage measured by controlcircuit 540 at terminal 544 may be approximately 0.7 volts (e.g., asingle diode drop). The control circuit 540 may compare the measuredvoltage of 0.7 volts at the terminal 544 to the first threshold V_(TH1).Since the measured voltage is less than the first threshold V_(TH1), thecontrol circuit 540 may determine that only one actuator (e.g., actuator501) is actuated.

If actuators 502 and 508 are pressed (e.g., the user accidently pressedtwo buttons at once or pressed two buttons on purpose), the magnitude ofthe voltage measured by the control circuit 540 at terminal 544 may beapproximately 1.4 volts (e.g., two diode drops) when the control circuitis trying to determine if actuator 501 is being pressed. The controlcircuit 540 may compare the measured voltage of 1.4 volts to the firstthreshold V_(TH1), the second threshold V_(TH2), and/or the thirdthreshold V_(TH3). Since the measured voltage is greater than the firstthreshold V_(TH1), the control circuit 540 may determine that a ghostingcondition is occurring. In addition, since the measured voltage is lessthan the second threshold V_(TH2), the control circuit 540 may determinethat two actuators are presently being actuated. Based on theconfiguration of the terminals (e.g., terminal 542 low and terminal 544pulled high) and the magnitude of the measured voltage (e.g., 1.4 voltsindicating two buttons pressed), the control circuit 540 may determinethat two actuators are being actuated (e.g., actuators 502 and 508).Upon determining the actuation of the two actuators 502 and 508, thecontrol circuit 540 may check to see if the actuation of actuators 502and 508 activates an advanced programming mode, or alternative, if itwas the result of user error. In another example, the control circuitmay mark a state of each actuator as open, actuated, or quarantined asthe control circuit compares the measured signal with the multiplethresholds and records the states of actuators 501-512 beforedetermining whether the actuation of actuators 502 and 508 activates anadvanced programming mode or is the product of user error.

If actuators 502, 509, and 511 are pressed (e.g., the user accidentlypressed three buttons at once or pressed three buttons on purpose), themagnitude of the voltage measured by the control circuit 540 at terminal544 may be approximately 2.1 volts (e.g., three diode drops) when thecontrol circuit is trying to determine if actuator 501 is being pressed.The control circuit 540 may compare the measured voltage of 2.1 volts tothe first threshold V_(TH1), the second threshold V_(TH2), and/or thethird threshold V_(TH3). Since the measured voltage is greater than thefirst threshold V_(TH1), the control circuit 540 may determine that aghosting condition is occurring. In addition, since the measured voltageis greater than the second threshold V_(TH2) and less than the thirdthreshold V_(TH3), the control circuit 540 may determine that threeactuators are presently being actuated. Based on the configuration ofthe terminals (e.g., terminal 542 low and terminal 544 pulled high) andthe magnitude of the measured voltage (e.g., 2.1 volts indicating threebuttons pressed), the control circuit 540 may determine that threeactuators are being actuated (e.g., actuators 502, 509, and 511). Upondetermining the actuation of the three actuators 502, 509, and 511, thecontrol circuit 540 may check to see if the actuation of actuators 502,509, and 511 activates an advanced programming mode. Alternatively, thecontrol circuit 540 may conclude that the actuation was the product ofuser error. In another example, the control circuit may mark a state ofeach actuator as open, actuated, or quarantined as the control circuitcompares the measured signal with each of the multiple thresholds andrecords the states of actuators 501-512 before determining whether theactuation of actuators 502, 509, and 511 activates an advancedprogramming mode or is the product of user error.

Alternatively, the control circuit 540 may configure the terminals542-546 differently prior to reading one of the terminals to determineif a particular actuator of the actuators 501-512 is presently beingactuated. For example, the control circuit 540 may configure a firstterminal that is connected to the anode of the diode in series with theparticular actuator as an output, and may short the terminal to thesupply voltage. The control circuit 540 may configure a second terminalthat is connected to the cathode of the diode in series with theparticular actuator as an input that is pulled down towards circuitcommon through an internal pull-down resistor, and may configure thesecond terminal as an ADC input. In addition, the control circuit 540may configure each of the remaining terminals to the high-impedancestate. In this example, the control circuit 540 may use three differentthresholds V_(TH4), V_(TH5), V_(TH6) when determining if a ghostingcondition is occurring. A measured voltage greater than the fourththreshold V_(TH4) may indicate a voltage drop of a single diode. Ameasured voltage less than the fourth threshold V_(TH4) and greater thanthe fifth threshold V_(TH5) may indicate a voltage drop of two diodes. Ameasured voltage less than the fifth threshold V_(TH5) and greater thansixth threshold V_(TH6) may indicate a voltage drop of three diodes. Ifthe supply voltage has a magnitude of 5 volts and the voltage dropassociated with each diode 521-532 is approximately 0.7 volts, then thefourth threshold V_(TH4) may be 4 volts, the fifth threshold V_(TH5) maybe 3.3 volts, and the sixth threshold V_(TH6) may be 2.6 volts.

FIG. 6 is a diagram of another example actuator input circuit 600 andexample control circuit 640 that may be configured to perform acharlieplexing technique and detect ghosting conditions. The controlcircuit 640 may be an example of the control circuit 414 of the controldevice 400, and the actuator input circuit 600 may be an example of theactuator input circuit 416 of the control device 400. The controlcircuit 640 (e.g., a processor, such as a microprocessor) may include aplurality of terminals, such as the four terminals 642, 644, 646, and648, while the analog input circuit 600 may include a plurality ofactuators 601-608 and a plurality of current regulating devices, such asdiodes 621-628. The control circuit 640 may be configured to perform thecharlieplexing technique with terminals 642-648 and detect a ghostingcondition, for example, as described with reference to the controlcircuit 540. The difference between the actuator input circuit 600 andthe actuator input circuit 500 is that the actuator input circuit 600includes less than the maximum number N_(MAX) of possible actuators(e.g., eight actuators 601-608 and associated diodes 621-628) as opposedto the twelve actuators 501-512 and associated diodes 521-532 shown inFIG. 5. The eight actuators 601-608 of the actuator input circuit 600shown in FIG. 6 may be arranged such that a ghosting condition cannotoccur in response to the actuation of two of the actuators at the sametime. Ghosting conditions may only occur in response to the actuation ofthree or more of the actuators 601-608 at the same time.

FIG. 7 is a flowchart illustrating an example control procedure 700 thatmay be executed by a control circuit of a control device (e.g., thecontrol circuit 414 of the control device 400, the control circuit 540,and/or the control circuit 640). The control circuit may execute thecontrol procedure 700 periodically (e.g., autonomously) and/or inresponse to receiving an indication (e.g., via one or more actuatorsand/or a communication circuit). During the control procedure 700, thecontrol circuit may use a variable n to keep track of a number ofactuators that are read. Based on a dataset that is created by thecontrol circuit using the control procedure 700, the control circuit maydetermine whether a ghosting condition has occurred, which may indicatean error.

At 702, the control circuit may start the control procedure (e.g.,autonomously or based on a receipt of an indication). At 704, thecontrol circuit may initialize the variable n to one (e.g., n=1). Thevariable n may have a maximum value N_(MAX) that is equal to the numberof actuators of the load control device, such that each value of n isassociated with a different actuator of the load control device. At 705,the control circuit may configure the terminals appropriately for thepresent actuator to be read (e.g., driven low, pulled-up high,high-impedance, etc.) as described above. At 706, the control circuitmay measure the magnitude of a voltage at a terminal, where an actuatormay be coupled between the terminal and another terminal. For example,the control circuit may compare the measured voltage with one or morethresholds X, Y (e.g., the thresholds V_(TH1), V_(TH2), respectively).The thresholds X, Y may have values based on a different number of diodedrops. For example, measured voltages less than the threshold X mayindicate a voltage drop of one diode and measured voltages greater thanthe threshold X and less than the threshold Y may indicate a voltagedrop of more than one diodes (e.g., two diodes). As such, threshold Ymay be a greater numerical value than threshold X.

At 708, the control circuit may compare the measured voltage to thethreshold X. If the control circuit determines that the measured voltageis less than the threshold X, the control circuit may mark a state ofthe actuator n as “closed” at 710. For example, the control circuit maymark the actuator n as actuated in a volatile or non-volatile memory forcomparison later to a predetermined dataset (e.g., table). If thecontrol circuit determines that the measured voltage is not less thanthe threshold X, the control circuit may compare the measured voltagewith the threshold Y at 712. If the control circuit determines that themeasured voltage is less than the threshold Y at 712, the controlcircuit may determine that a ghosting condition has occurred and markthe state of the actuator n as “quarantined” at 716. If the controlcircuit determines that the measured voltage is not less than thethreshold Y at 712, the control circuit may mark the state of theactuator n as “open” at 714.

At 718, the control circuit may determine whether n is equal to N_(MAX).If the control circuit determines that n is not equal to N_(MAX) (e.g.,n is less than N_(MAX)), then the control circuit may increment n at 720and perform 705-716 again with an incremented value of the variable n.For example, the control circuit may perform 705-716 again at adifferent terminal associated with a different actuator. If the controlcircuit determines that n is equal to N_(MAX) at 718, then the controlcircuit may determine that all actuators have been read andcharacterized, and proceeds to 722.

At 722, the control circuit may compare the states of the markedactuators (e.g., “closed,” “open,” or “quarantined” for each of theactuators of the load control device) to the preconfigured dataset todetermine whether the states of the marked actuators are valid. Thestates of the marked actuators may be valid if a valid current path canbe formed based on the states of the marked actuators is valid.

The preconfigured dataset may include valid combinations of states foreach actuator (e.g., combinations corresponding to valid actuations ofone or more actuators by a user). For example, one combination in thedataset may include a state of “open” for each actuator, indicating theuser did not actuate any of the actuators. For further example, acombination may include a state of “open” for all but one actuator and astate of “closed” for a single actuator, indicating that the useractuated a single actuator and a ghosting condition did not occur.Further, there may be some combinations that correspond to advancedprogramming modes. These combinations may include multiple actuatorswith a state of “closed”, one or more actuators with a state of “open”,and one or more actuators with a state of “quarantined.”

If the control circuit determines that the states of the actuators arevalid at 722, the control circuit may perform a function associated withthe states of the actuators (e.g., associated function) at 724. Thevalidation of the states of the actuators may include checking whetherhardware supports the associated function and/or the associated functionis enabled based on rules. The rules may entail whether a validcombination of the states of the actuators enables an advancedprogramming mode for the load control device. The associated functionmay include a function performed by the load control devicecorresponding to an actuation of a single actuator. The associatedfunction may include an advanced programming mode corresponding to anactuation of multiple actuators. The advanced programming mode may, forexample, be used by a technician or user to add, remove, or changefeatures of the load control device. In another example, an advancedprogramming mode may automatically switch an operating mode of the loadcontrol device.

If the control circuit determines that the states of the actuators arenot valid at 722, the control circuit may determine an error hasoccurred at 726. For example, the control circuit may determine that thecombination of states of actuators is invalid if multiple actuators areindicated as actuated and/or one or more actuators are marked asquarantined, and the combination of the states of the actuators do notmatch one of the combinations in the dataset. If the control circuitdetermines an error has occurred at 726, then the control circuit, at728, may notify a user of the load control device that the error hasoccurred. For example, the control circuit may illuminate and/or flashan LED of the load control device, play an audible noise via the loadcontrol device, transmit a digital message, etc. Further, if the controlcircuit determines an error has occurred at 726, the control circuit maynot adjust any of the electrical loads of the system. The controlcircuit may exit the control procedure 700 at 730.

One will understand that the methods described herein are for exampleonly, and the embodiments are not limited to the number of actuatorsshown, but also may be applied to a device having any number N terminalson a control circuit and up to N(N−1) actuators.

What is claimed is:
 1. A charlieplex method, comprising: for each of aplurality of I/O connections, each of the plurality of I/O connectionsconductively coupled to a plurality of actuator circuits, each of theplurality of actuator circuits including an actuator coupled inelectrical series with at least one current limiting device: providing,by control circuitry, a supply voltage at the I/O connection; and foreach of the remaining plurality of I/O connections: measuring, by thecontrol circuitry, a voltage at the respective I/O connection;determining, by the control circuitry, whether the measured voltage atthe respective I/O connection is less than a first voltage threshold;responsive to the determination that the measured voltage at therespective I/O connection is less than the first voltage threshold,returning, by the control circuitry, a logical value indicative that theactuator circuit presently conductively coupled between the voltagesupply I/O connection and the respective I/O connection is in anelectrically CLOSED state; and uniquely identifying the actuator circuitbased on the voltage supply I/O connection and the respective I/Oconnection.
 2. The method of claim 1, further comprising: responsive tothe determination that the measured input voltage at the respective I/Oconnection is greater than the first voltage threshold, determining, bythe control circuitry, whether the measured input voltage at therespective I/O connection is less than a second voltage threshold, thesecond voltage threshold greater than the first voltage threshold. 3.The method of claim 2, further comprising: responsive to thedetermination that the measured input voltage at the respective I/Oconnection is less than the second voltage threshold, returning, by thecontrol circuitry, a logical value indicative that the actuatorpresently conductively coupled between the voltage supply I/O connectionof the respective I/O connection is in a QUARANTINE state.
 4. The methodof claim 3, further comprising: for each of the actuator circuitsidentified as in the QUARANTINE state: comparing, by the controlcircuitry, the identity of the actuator circuit identified as in theQUARANTINE state with a historical dataset stored in a memory circuitrycommunicatively coupled to the control circuitry; and determining, bythe control circuitry, that an error has occurred when the identity ofthe actuator circuit identified as in the QUARANTINE state differs fromthe historical dataset.
 5. The method of claim 2, further comprising:responsive to the determination that the measured input voltage at therespective I/O connection is greater than the second voltage threshold,returning, by the control circuitry, a logical value indicative that theactuator circuit presently conductively coupled between the voltagesupply I/O connection of the respective I/O connection is in anelectrically OPEN state.
 6. The method of claim 1 wherein providing, bycontrol circuitry, the supply voltage at the voltage supply I/Oconnection further comprises: providing, by the control circuitry, thesupply voltage at the respective one of “N” I/O connections where “N” isan integer number greater than 2, wherein each of the plurality of I/Oconnections is conductively coupled to N−1 circuits.
 7. A load controldevice to control power delivered to one or more electrical loads, theload control device comprising: a plurality of actuator circuits, eachof the plurality of actuator circuits including an actuator connected inelectrical series with a current regulating device; and a controlcircuit comprising a plurality of I/O connections, each of the pluralityof I/O connections conductively coupled to each of at least a portion ofthe plurality of actuator circuits, the control circuit to: for each ofa plurality of I/O connections, provide a supply voltage at therespective I/O connection; and for each of the remaining plurality ofI/O connections: measure an input voltage at the respective I/Oconnection; determine whether the measured input voltage at therespective I/O connection is less than a first voltage threshold; andresponsive to the determination that the measured input voltage at therespective I/O connection is less than the first voltage threshold,return a logical value indicative that the actuator included in theactuator circuit presently conductively coupled between the voltagesupply I/O connection and the respective input I/O connection is in anelectrically CLOSED state.
 8. The load control device of claim 7, thecontrol circuitry to further: responsive to the determination that themeasured input voltage at the respective input I/O connection is greaterthan the first voltage threshold, determine whether the measured inputvoltage at the respective I/O connection is less than a second voltagethreshold, the second voltage threshold greater than the first voltagethreshold.
 9. The load control device of claim 8, the control circuitryto further: return a logical value indicative that the actuatorpresently conductively coupled between the voltage supply I/O connectionof the respective input I/O connection is in a QUARANTINE stateresponsive to the determination that the measured input voltage at therespective input I/O connection is less than the second voltagethreshold.
 10. The load control device of claim 9, the control circuitryto further: for each of the actuator circuits identified as in theQUARANTINE state: compare the identity of the actuator circuitidentified as in the QUARANTINE state with a historical dataset storedin a memory circuitry communicatively coupled to the control circuitry;and determine that an error has occurred when the identity of theactuator circuit identified as in the QUARANTINE state differs from thehistorical dataset.
 11. The load control device of claim 8, the controlcircuitry to further: return a logical value indicative that theactuator presently conductively coupled between the voltage supply I/Oconnection of the respective input I/O connection is in an electricallyOPEN state responsive to the determination that the measured inputvoltage at the respective input I/O connection is greater than thesecond voltage threshold.
 12. The load control device of claim 7 whereinto provide the supply voltage at the respective I/O connection, thecontrol circuitry to further: provide the supply voltage at one of “N”I/O connections where “N” is an integer number greater than 2, whereineach of the plurality of I/O connections conductively couples to “N−1”circuits.
 13. A non-transitory, machine-readable, storage device thatincludes instructions that, when executed by control circuitryconductively coupled to each of a plurality of I/O connections, each ofthe plurality of I/O connections conductively coupled to a plurality ofactuator circuits, each of the plurality of actuator circuits includingan actuator coupled in electrical series with at least one currentlimiting device, cause the control circuitry to: for each of theplurality of I/O connections, provide a supply voltage at the respectiveI/O connection; and for each of the remaining plurality of I/Oconnections: measure an input voltage at the respective I/O connection;determine whether the measured input voltage at the respective I/Oconnection is less than a first voltage threshold; and responsive to thedetermination that the measured input voltage at the respective I/Oconnection is less than the first voltage threshold, return a logicalvalue indicative that the actuator included in the actuator circuitpresently conductively coupled between the voltage supply I/O connectionand the respective input I/O connection is in an electrically CLOSEDstate.
 14. The non-transitory, machine-readable, storage device of claim13, wherein the instructions further cause the control circuitry to:responsive to the determination that the measured input voltage at therespective I/O connection is greater than the first voltage threshold,determine whether the measured input voltage at the respective I/Oconnection is less than a second voltage threshold, the second voltagethreshold greater than the first voltage threshold.
 15. Thenon-transitory, machine-readable, storage device of claim 14 wherein theinstructions further cause the control circuitry to: return a logicalvalue indicative that the actuator circuit presently conductivelycoupled between the voltage supply I/O connection and the respective I/Oconnection is in a QUARANTINE state responsive to the determination thatthe measured input voltage at the respective I/O connection is less thanthe second voltage threshold.
 16. The non-transitory, machine-readable,storage device of claim 15 wherein the instructions further cause thecontrol circuitry to: for each of the actuator circuits identified as inthe QUARANTINE state: compare the identity of the actuator circuitidentified as in the QUARANTINE state with a historical dataset storedin a memory circuitry communicatively coupled to the control circuitry;and determine that an error has occurred when the identity of theactuator circuit identified as in the QUARANTINE state differs from thehistorical dataset.
 17. The non-transitory, machine-readable, storagedevice of claim 14 wherein the instructions further cause the controlcircuitry to: return a logical value indicative that the actuatorcircuit presently conductively coupled between the voltage supply I/Oconnection and the respective I/O connection is in an electrically OPENstate responsive to the determination that the measured input voltage atthe respective I/O connection is greater than the second voltagethreshold.
 18. The non-transitory, machine-readable, storage device ofclaim 13 wherein the instructions that cause the control circuitry toprovide the supply voltage at the I/O connection, further cause thecontrol circuitry to: supply a supply voltage at one of “N” I/Oconnections where “N” is an integer number greater than 2, wherein eachof the plurality of I/O connections conductively couples to “N−1”circuits.